Glyphosate is an organophosphorus compound that is used to kill weeds, especially annual broadleaf weeds and grasses that compete with crops. First synthesized in 1950 by a Swiss chemist, the U.S. company Monsanto began marketing in 1974 an agricultural herbicide in which glyphosate is the main active ingredient under the trade name Roundup. Glyphosate is currently the most extensively used herbicide in United States agricultural and the second-most used for home and other applications. It is particularly effective when used with crops that have been genetically engineered to be resistant to it.
Although the glyphosate has been approved by governments in many countries, concern about its adverse effects on humans and the environment has persisted. Some studies have shown a positive correlation between exposure to products containing glyphosate and the risk of various cancers, eye damage, and toxicity to aquatic life. Its widespread use has also resulted in the emergence and proliferation of weeds which are resistant to it, thus requiring larger and larger quantities to be used. These concerns have resulted in an an increasing number of countries restricting or banning its use.